1. Field of the Invention
This invention relates to underground mining operations, and more particulary to a method for controlling a mine roof by inducing controlled roof caving over mined out areas.
2. Description of the Prior Art
Methods for controlling caving of mined out areas are described in U.S. Pat. Nos. 3,402,968 and 3,673,807.
A method utilizing hydraulic fracturing between boreholes to provide communication between boreholes in a solution mining process is described in U.S. Pat. No. 3,058,730.
Methods for controlling caving during mining of trona are described in U.S. Pat. Nos. 3,026,096; 3,097,830 and 3,111,306.
None of the above-noted patents suggests protecting a mine entryway by inducing additional roof caving by hydraulic fracturing of the mine roof formation.